ASP.NET Common Interview Questions and Answers

Life cycle of an ASP .NET page.

Stage Events/Method

Page Initialization Page_Init

View State Loading LoadViewState

Postback data processin LoadPostData

Page Loading Page_Load

PostBack Change Notification RaisePostDataChangedEvent

PostBack Event Handling RaisePostBackEvent

Page Pre Rendering Phase Page_PreRender

View State Saving SaveViewState

Page Rendering Page_Render

Page Unloading Page_UnLoad

1) Explain the .NET architecture.

a) All .Net supported Languages

b) Common Language specification

c) Windows forms / web pages

d) ADO.Net / web services

e) Base class library

f) Common language runtime

g) Operating system.

2) How does u create multiple inheritances in c# and .net?

Multiple inheritances are created by using interfaces.

3) When web.config is called ?

Web.config is an xml configuration file.this never gets called directly unless we need to retrieve the configuration setting.

4) How many weg.configs a application can have

one.

5) How does u set language in weg.config

a) set the ‘defaultlanguage’ attribute.

6) What does connection string consists of

a) connection string consist of : server name, userid , password , database name.

7) Where do u store connection string

a) connection string can stored in web.config file under configuration / connection string tab.

8) What is abstract class?

Abstract class is a class which cannot be instantiated but inherited by derived classes. This class contains abstract as well as non-abstract methods and members.

9) What is diff b/w interface inheritance and class inheritance

A class can have multiple interface inheritance, but only one.

In interface inheritance : Inherited class must implement all the methods define in that interface. Class inheritance : inherited class may or may not implement all methods of that base class.

10) What are the collection classes?

1) Array list

2) Hash table

3) stack

4) Dictionary

5) Queue

12) What inheritance support vb.net?

a) Single class inheritance and multiple interface inheritance.

13) What is runtime host?

a) Runtime host is local environment where CLR is running.

14) OOPS CONCEPTS

1) Encapsulation : Hiding internal implementation of the objects and provide global interface access to object.

2) Inheritance : The ability of a class to reuse the members and member functions of its base class.

3) Polymorphism : The ability of the objects to be represented in multiple forms. This is possible with overriding and overloading.

4) Abstraction : Describing an object with its unique and relevant characteristics according to specific need.

Object-Oriented concepts?

Class: The formal definition of an object. The class acts as the template from which an instance of an object is created at run time. The class defines the properties of the object and the methods used to control the object’s behaviour.

Object: An object is an instance of a class.

Encapsulation: hides detailed internal specification of an object, and publishes only its external interfaces. Thus, users of an object only need to adhere to these interfaces. By encapsulation, the internal data and methods of an object can be changed without changing the way of how to use the object.

Inheritance: A class that derives from another class - known as the base class - inherits the same methods and properties. This promotes reuse and maintainability.

Abstraction: the describing of objects by defining their unique and relevant characteristics (properties). Whilst an object may have 100s of properties normally only those properties of importance to the situation are described. (eg life policies premiums are normally important; whereas the time of day a policy was purchased is not usually of value).

Polymorphism: Allows objects to be represented in multiple forms. Even though classes are derived or inherited from the same parent class, each derived class will have its own behavior. (Overriding and hiding methods)

15) optimization technique description

1) Avoid unnecessary use of view state which lowers the performance.

2) Avoid the round trips to server.

3) Use connection pooling.

4) Use stored procedures.

16) Diff b/w application and session

a) Application object maintains state on application basis whereas session object maintain the state of the client visited to the application.

17) What is web application virtual directory?

a) Virtual directory is a physical location where actually application folder is situated.

18) Diff b/w Active.exe and Dll

1) Exe has an entry point.

2) If Dll is getting destroyed, exe also destroyed.

20) If cookies are disabled in client browser will session work

a) No. Identities of client gets destroy.

23) The following code executes successfully

response. Write (“value of i=”+i) ;

a) Yes.

25) What are a Process, Session and Cookie?

1) Process : Is a running thread of application.

2) Session : state used to maintain user state in application.

3) cookie : used to store user identification data on client machine.

29) How is Polymorphism supports in .net?

Polymorphism supports to objects to be represent in different forms..

30) What r the 2 types of polymorphism support in .net?

Overriding and overloading

35) ASP.NET OBJECTS?

Request, Response, Server, Session, application,

38) What is side by side execution

Asynchronous execution in which application keeps on running instead of waiting for the result of previous stage execution.

39) What serialization?

Serialization is a process of conversion an objects into stream of bytes so that they can transfer through the channels.

40) About a class access specifiers and method access specifiers

1) Public : available throughout application.

2) Private : available for class and its inherited class.

3) Protected : restricted to that class only.

4) Internal : available throughout that assembly.

41) What diff b/w overloading and overriding? How can this be .net

Overriding : derived classes follow the same base class method signatures.

Overloading : Derived classes may have different method signature with different parameters.

42) About virtual function and then use

Virtual function is that which is get override by the derived class to implement polymorphism.

How do u implement inheritance in .net?

In c# : we use :

44)if I want to override a method 1 of class A and this class B then how do u declared

answer :

public virtual void method1(){ } ..In class A. public override void method1(){}…………..In class B.

45) About friend and protected friend

Friend / internal : provides access throughout that particular assembly.

Protected friend : provides access for that particular class and to its child classes.

46) About multiple and multilevel Inheritance how to a chive in .net?

Multiple Inheritance: ex. Public void Employee : Persons, Iemployee. Means a class can be inherited by more than one interface OR inherited by one class and

more than one interfaces.

Multi level inheritance: ex. Public void Person () {}, Public void Customer : person {} , Public void employee : customer{}.

50) What is isPostback property?

Is postback is a property of page to check weather the page is loaded first time or in response to the client callback.

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OOPS Common Interview Questions and Answers

1. What is the difference between procedural and object-oriented programs?- a) In procedural program, programming logic follows certain procedures and the instructions are executed one after another. In OOP program, unit of program is object, which is nothing but combination of data and code. b) In procedural program, data is exposed to the whole program whereas in OOPs program, it is accessible with in the object and which in turn assures the security of the code.
2. What are Encapsulation, Inheritance and Polymorphism?- Encapsulation is the mechanism that binds together code and data it manipulates and keeps both safe from outside interference and misuse. Inheritance is the process by which one object acquires the properties of another object. Polymorphism is the feature that allows one interface to be used for general class actions.
3. What is the difference between Assignment and Initialization?- Assignment can be done as many times as desired whereas initialization can be done only once.
4. What is OOPs?- Object oriented programming organizes a program around its data, i. e. , objects and a set of well defined interfaces to that data. An object-oriented program can be characterized as data controlling access to code.
5. What are Class, Constructor and Primitive data types?- Class is a template for multiple objects with similar features and it is a blue print for objects. It defines a type of object according to the data the object can hold and the operations the object can perform. Constructor is a special kind of method that determines how an object is initialized when created. Primitive data types are 8 types and they are: byte, short, int, long, float, double, boolean, char.
6. What is an Object and how do you allocate memory to it?- Object is an instance of a class and it is a software unit that combines a structured set of data with a set of operations for inspecting and manipulating that data. When an object is created using new operator, memory is allocated to it.
7. What is the difference between constructor and method?- Constructor will be automatically invoked when an object is created whereas method has to be called explicitly.
8. What are methods and how are they defined?- Methods are functions that operate on instances of classes in which they are defined. Objects can communicate with each other using methods and can call methods in other classes. Method definition has four parts. They are name of the method, type of object or primitive type the method returns, a list of parameters and the body of the method. A method’s signature is a combination of the first three parts mentioned above.
9. How many ways can an argument be passed to a subroutine and explain them?- An argument can be passed in two ways. They are passing by value and passing by reference. Passing by value: This method copies the value of an argument into the formal parameter of the subroutine. Passing by reference: In this method, a reference to an argument (not the value of the argument) is passed to the parameter.
10. What is the difference between an argument and a parameter?- While defining method, variables passed in the method are called parameters. While using those methods, values passed to those variables are called arguments.
11. What are different types of access modifiers?- public: Any thing declared as public can be accessed from anywhere. private: Any thing declared as private can’t be seen outside of its class. protected: Any thing declared as protected can be accessed by classes in the same package and subclasses in the other packages. default modifier : Can be accessed only to classes in the same package.
12. What are Transient and Volatile Modifiers?- Transient: The transient modifier applies to variables only and it is not stored as part of its object’s Persistent state. Transient variables are not serialized. Volatile: Volatile modifier applies to variables only and it tells the compiler that the variable modified by volatile can be changed unexpectedly by other parts of the program.
13. What is method overloading and method overriding?- Method overloading: When a method in a class having the same method name with different arguments is said to be method overloading. Method overriding : When a method in a class having the same method name with same arguments is said to be method overriding.
14. What is difference between overloading and overriding?- a) In overloading, there is a relationship between methods available in the same class whereas in overriding, there is relationship between a superclass method and subclass method. b) Overloading does not block inheritance from the superclass whereas overriding blocks inheritance from the superclass. c) In overloading, separate methods share the same name whereas in overriding, subclass method replaces the superclass. d) Overloading must have different method signatures whereas overriding must have same signature.
15. What is meant by Inheritance and what are its advantages?- Inheritance is the process of inheriting all the features from a class. The advantages of inheritance are reusability of code and accessibility of variables and methods of the super class by subclasses.
16. What is the difference between this() and super()?- this() can be used to invoke a constructor of the same class whereas super() can be used to invoke a super class constructor.
17. What is the difference between superclass and subclass?- A super class is a class that is inherited whereas sub class is a class that does the inheriting.
18. What modifiers may be used with top-level class?- public, abstract and final can be used for top-level class.
19. What are inner class and anonymous class?- Inner class : classes defined in other classes, including those defined in methods are called inner classes. An inner class can have any accessibility including private. Anonymous class : Anonymous class is a class defined inside a method without a name and is instantiated and declared in the same place and cannot have explicit constructors.
20. What is interface and its use?- Interface is similar to a class which may contain method’s signature only but not bodies and it is a formal set of method and constant declarations that must be defined by the class that implements it. Interfaces are useful for: a)Declaring methods that one or more classes are expected to implement b)Capturing similarities between unrelated classes without forcing a class relationship. c)Determining an object’s programming interface without revealing the actual body of the class.
21. What is an abstract class?- An abstract class is a class designed with implementation gaps for subclasses to fill in and is deliberately incomplete.
22. What is the difference between abstract class and interface?- a) All the methods declared inside an interface are abstract whereas abstract class must have at least one abstract method and others may be concrete or abstract. b) In abstract class, key word abstract must be used for the methods whereas interface we need not use that keyword for the methods. c) Abstract class must have subclasses whereas interface can’t have subclasses.
23. Can you have an inner class inside a method and what variables can you access?- Yes, we can have an inner class inside a method and final variables can be accessed.
24. What is the difference between Array and vector?- Array is a set of related data type and static whereas vector is a growable array of objects and dynamic.
25. What is the difference between exception and error?- The exception class defines mild error conditions that your program encounters. Exceptions can occur when trying to open the file, which does not exist, the network connection is disrupted, operands being manipulated are out of prescribed ranges, the class file you are interested in loading is missing. The error class defines serious error conditions that you should not attempt to recover from. In most cases it is advisable to let the program terminate when such an error is encountered.
26. What is the difference between process and thread?- Process is a program in execution whereas thread is a separate path of execution in a program.
27. What is multithreading and what are the methods for inter-thread communication and what is the class in which these methods are defined?- Multithreading is the mechanism in which more than one thread run independent of each other within the process. wait (), notify () and notifyAll() methods can be used for inter-thread communication and these methods are in Object class. wait() : When a thread executes a call to wait() method, it surrenders the object lock and enters into a waiting state. notify() or notifyAll() : To remove a thread from the waiting state, some other thread must make a call to notify() or notifyAll() method on the same object.

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JAVA Common Interview Questions and Answers

What is the difference between procedural and object-oriented programs?- a) In procedural program, programming logic follows certain procedures and the instructions are executed one after another. In OOP program, unit of program is object, which is nothing but combination of data and code. b) In procedural program, data is exposed to the whole program whereas in OOPs program, it is accessible with in the object and which in turn assures the security of the code.

What is the difference between Assignment and Initialization?- Assignment can be done as many times as desired whereas initialization can be done only once.

What is the difference between constructor and method?- Constructor will be automatically invoked when an object is created whereas method has to be called explicitly.

What is the difference between an argument and a parameter?- While defining method, variables passed in the method are called parameters. While using those methods, values passed to those variables are called arguments.

What is the difference between overloading and overriding?- a) In overloading, there is a relationship between methods available in the same class whereas in overriding, there is relationship between a superclass method and subclass method. b) Overloading does not block inheritance from the superclass whereas overriding blocks inheritance from the superclass. c) In overloading, separate methods share the same name whereas in overriding, subclass method replaces the superclass. d) Overloading must have different method signatures whereas overriding must have same signature.

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What is the difference between this() and super()?- this() can be used to invoke a constructor of the same class whereas super() can be used to invoke a super class constructor.

FRESHER OFF-CAMPUS & MEGA JOB FAIRS - 2011

What is the difference between superclass and subclass?- A super class is a class that is inherited whereas sub class is a class that does the inheriting.

What is the difference between String and String Buffer?- a) String objects are constants and immutable whereas StringBuffer objects are not. b) String class supports constant strings whereas StringBuffer class supports growable and modifiable strings.

What is the difference between Array and vector?- Array is a set of related data type and static whereas vector is a growable array of objects and dynamic.

What is the difference between exception and error?- The exception class defines mild error conditions that your program encounters. Exceptions can occur when trying to open the file, which does not exist, the network connection is disrupted, operands being manipulated are out of prescribed ranges, the class file you are interested in loading is missing. The error class defines serious error conditions that you should not attempt to recover from. In most cases it is advisable to let the program terminate when such an error is encountered.

What is the difference between process and thread?- Process is a program in execution whereas thread is a separate path of execution in a program.

What is the difference between abstract class and interface?- a) All the methods declared inside an interface are abstract whereas abstract class must have at least one abstract method and others may be concrete or abstract. b) In abstract class, key word abstract must be used for the methods whereas interface we need not use that keyword for the methods. c) Abstract class must have subclasses whereas interface can’t have subclasses.

What is the difference between Integer and int?- a) Integer is a class defined in the java. lang package, whereas int is a primitive data type defined in the Java language itself. Java does not automatically convert from one to the other. b) Integer can be used as an argument for a method that requires an object, whereas int can be used for calculations.

What is the difference between choice and list?- A Choice is displayed in a compact form that requires you to pull it down to see the list of available choices and only one item may be selected from a choice. A List may be displayed in such a way that several list items are visible and it supports the selection of one or more list items.

What is the difference between scrollbar and scrollpane?- A Scrollbar is a Component, but not a Container whereas Scrollpane is a Conatiner and handles its own events and perform its own scrolling.

What is the difference between applications and applets?- a)Application must be run on local machine whereas applet needs no explicit installation on local machine. b)Application must be run explicitly within a java-compatible virtual machine whereas applet loads and runs itself automatically in a java-enabled browser. d)Application starts execution with its main method whereas applet starts execution with its init method. e)Application can run with or without graphical user interface whereas applet must run within a graphical user interface.

What is the difference between set and list?- Set stores elements in an unordered way but does not contain duplicate elements, whereas list stores elements in an ordered way but may contain duplicate elements.

What is the difference between an applet and a servlet?- a) Servlets are to servers what applets are to browsers. b) Applets must have graphical user interfaces whereas servlets have no graphical user interfaces.

What is the difference between doPost and doGet methods?- a) doGet() method is used to get information, while doPost() method is used for posting information. b) doGet() requests can’t send large amount of information and is limited to 240-255 characters. However, doPost()requests passes all of its data, of unlimited length. c) A doGet() request is appended to the request URL in a query string and this allows the exchange is visible to the client, whereas a doPost() request passes directly over the socket connection as part of its HTTP request body and the exchange are invisible to the client.

What is the difference between TCP/IP and UDP?- TCP/IP is a two-way communication between the client and the server and it is a reliable and there is a confirmation regarding reaching the message to the destination. It is like a phone call. UDP is a one-way communication only between the client and the server and it is not a reliable and there is no confirmation regarding reaching the message to the destination. It is like a postal mail.

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Walkin for Java Freshers in Chennai - 2011 Freshers Walkin - Jobs for Software Freshers in Chennai

Spiro Solutions Recruiting Fresher Java Developer

Experience: 0 Years
Location: Chennai
Education: B.E/B.Tech/BCA/MCA/B.Sc/M.SC
Functional Area: Application Programming, Maintenance

Job Description :
Working as a Java Developer

Desired Candidate Profile ;
2011 passout Candidates, 
should have basic knowledge of Core Java, EJB. With good communication skills, Innovate bent of mind, Analytical and Problem solving skills. Candidates should being with chennai.

Contact Details :
Company Name: SPIRO SOLUTIONS PVT LTD
Website: http://www.spiroit.com
Executive Name: Ms.M.Eshwari

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